Stresslinux community

Hello everyone,
I want to run a script as my server boots up with PXE.
The thing is that when change the content it doesn't boot up saying that md5 isn't correct. Though i've been trying to rehash the file with md5hash command.
Can anybody help me out? Maybe there's something built into stresslinux image I need to change as well?

This is a KIWI related question, please ask on https://groups.google.com/forum/#!forum/kiwi-images

Though i've been trying to rehash the file with md5hash command.